Occurrence of Rhizomorphs of Armillaria in Soils from Declining Red Spruce Stands in Three Forest Types

Plant Disease ◽  
1987 ◽  
Vol 71 (2) ◽  
pp. 163 ◽  
Author(s):  
P. M. Wargo
1986 ◽  
Vol 64 (4) ◽  
pp. 760-768 ◽  
Author(s):  
G. F. Bills ◽  
G. I. Holtzman ◽  
O. K. Miller Jr.

Sporocarps of Basidiomycetes belonging to families containing some species known to form ectomycorrhizae were enumerated in 12 plots (16 × 16 m) subdivided into contiguous 2 × 2 m quadrats during the growing seasons of 1981 – 1983. Plots were distributed equally between homogeneous second-growth red spruce stands and heterogeneous northern hardwood stands in southeastern West Virginia. A few major species accounted for most of the abundance, while most species fruited rarely, but abundance and phenology varied broadly from year to year, apparently in response to rainfall and temperature. Fungal species composition, spatial frequency, and sporocarp density in the two forest types differed as would be expected in light of the symbiotic nature of the fungi and trees considered. Of 54 fungal species encountered over 3 years, 19 occurred exclusively in spruce plots, 27 occurred exclusively in hardwood plots, and 8 occurred in both forest types. In both forest types, approximately 40% of the species were Russulaceae. Species frequency and sporocarp abundance were greater in spruce plots than in hardwood plots. The Shannon–Wiener index, the dominance–diversity curve, the species–area curve, and ordination confirmed that fungal species richness, equitability, and diversity were greater in the mixed-hardwood plots, which hosted many rare fungal species, than in the single-species coniferous plots, which were dominated by a few ubiquitous fungal species.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 841
Author(s):  
Iveta Desaine ◽  
Annija Kārkliņa ◽  
Roberts Matisons ◽  
Anna Pastare ◽  
Andis Adamovičs ◽  
...  

The increased removal of forest-derived biomass with whole-tree harvesting (WTH) has raised concerns about the long-term productivity and sustainability of forest ecosystems. If true, this effect needs to be factored in the assessment of long-term feasibility to implement such a drastic forest management measure. Therefore, the economic performance of five experimental plantations in three different forest types, where in 1971 simulated WTH event occurred, was compared with pure, planted and conventionally managed (CH) Norway spruce stands of similar age and growing conditions. Potential incomes of CH and WTH stands were based on timber prices for period 2014–2020. However, regarding the economics of root and stump biomass utilization, they were not included in the estimates. In any given price level, the difference of internal rate of return between the forest types and selected managements were from 2.5% to 6.2%. Therefore, Norway spruce stands demonstrate good potential of independence regardless of stump removal at the previous rotation.


2003 ◽  
Vol 135 (3) ◽  
pp. 337-357 ◽  
Author(s):  
J.L. Pearce ◽  
L.A. Venier ◽  
J. McKee ◽  
J. Pedlar ◽  
D. McKenney

AbstractStudies based on presence/absence of a species may provide insight into habitat associations, allowing the distribution of species to be predicted across the landscape. Our objective was to characterize the carabid fauna in three mature boreal forest types (conifer, mixedwood, and deciduous) and a disturbed habitat (clearcut) to provide baseline data on the carabid species inhabiting the major forest types of boreal northwestern Ontario. Only spring-active carabids were considered for logistical reasons. We further identified the coarse woody debris structure and microhabitat characteristics within these stand types to try to refine our ability to predict the within-stand occurrence of carabids. We found the carabid composition of deciduous stands (mixedwood and aspen) similar and typical of the carabid fauna found in mixedwood forest in other nearby studies. The important feature of these forest types may be the presence of a deciduous leaf litter layer. In contrast, spruce stands contained fewer species and individuals and a distinct carabid fauna. As predicted, the clearcut habitats were dominated by open habitat species, although the fauna was dissimilar to what was recorded in clearcut habitats in other studies within northwestern Ontario. Coarse woody debris appeared to be an important habitat attribute for several carabid species in clearcut habitats.


2005 ◽  
Vol 83 (9) ◽  
pp. 1096-1105 ◽  
Author(s):  
Om P. Rajora ◽  
Ishminder K. Mann ◽  
Yong-Zhong Shi

White spruce ( Picea glauca (Moench) Voss) is a characteristic primary species of the Canadian boreal forest region, where it occurs in conifer-dominated and mixedwood forest types. Genetic diversity and population structure of white spruce may differ between the conifer-dominated and mixedwood forest types owing to the inherent differences in stand structure and dynamics. The objective of our study was to determine genetic diversity and population structure of pristine white spruce stands as they occur in conifer-dominated and mixedwood forest types at the EMEND (Ecosystem Management Emulating Natural Disturbance) study sites in northern Alberta. Nuclear microsatellite DNA markers were used to examine genetic diversity and population structure of 16 pristine natural old-growth (≥100 years) white spruce stands (subpopulations) of fire origin; 8 from conifer-dominated and 8 from neighboring mixedwood forest types. High levels of genetic diversity were observed, as expected. The genetic diversity and genetic constitution of white spruce were similar between the conifer-dominated and mixedwood forest types. Most of the genetic variation resided within subpopulations, with only about 2% genetic differentiation detected among 16 subpopulations as well as among 8 subpopulations within the same forest type. The mean genetic distances among subpopulations within and between the forest types were similar. Our study suggests that white spruce genetic resources are similar in the conifer-dominated and mixedwood forest types located in the EMEND study area in northern Alberta, and it provides the benchmarks for determining and monitoring the genetic diversity impacts of forest harvesting and forest fires.


2003 ◽  
Vol 79 (3) ◽  
pp. 462-474 ◽  
Author(s):  
J. Loo ◽  
N. Ives

The Acadian Forest Region comprises the three Maritime Provinces of Canada, each of which has a distinct history resulting in different patterns of land ownership, land use, and impacts on the forest. The region encompasses a high degree of physiographic and biological diversity, being situated where the warm, moist influence of the Gulf Stream from the south collides with the cold Labrador Current and the boreal forest gradually gives way to mostly deciduous forest. Natural forest types in the Acadian Forest Region include rich tolerant hardwood, similar to the deciduous forests to the south; spruce-fir forest, similar to boreal forest to the north; and an array of coniferous, deciduous, and mixed intermediate types. Red spruce (Picea rubens Sarg.), yellow birch (Betula alleghaniensis Britt.), sugar maple (Acer saccharum Marsh.) and balsam fir (Abies balsamea (L.) Mill.) are considered characteristic of the Acadian Forest Region. Except for one quantitative study in one county of New Brunswick, and another study on Prince Edward Island, most knowledge of the historical forest condition has been gleaned from early descriptions by explorers, surveyors, and settlers of the Maritimes region. Although some regions have been affected much more than others, little, if any forested area has escaped human influence over the past four centuries. A general result of human activities has been a shift in successional status and age distribution, with increased frequency of relatively young, often even-aged, early successional forest types including balsam fir, white spruce (Picea glauca (Moench) Voss), red maple (Acer rubrum L.), white birch (Betula papyrifera Marsh.), and trembling aspen (Populus tremuloides Michx.). Both the abundance and age of late-successional species such as sugar maple, red spruce, eastern hemlock (Tsuga canadensis L. Carrière), yellow birch, cedar (Thuja occidentalis L.), and beech (Fagus grandifolia Ehrh.) have declined. Key words: pre-European forest, Maritime Provinces, historical ecology, witness trees, Acadian forest types, natural disturbance


2021 ◽  
Vol 941 (1) ◽  
pp. 012007
Author(s):  
D.A. Danilov ◽  
A.A. Yakovlev ◽  
L. S. Bogdanova ◽  
A.K. Boitsov ◽  
S.A. Suvorov

Abstract Pine- and spruce-dominatedmixed stands occupy a substantial part of the forested area. Depending on soil and hydrological conditions of different landscapes, stands of different forest types and tree stand composition dominate. Modern forestry is focused on growing monodominant stands, but it is worth noting that mixed stands have higher productivity and stability. This work is devoted to identifying the patterns of distribution of mixed stands by forest type in different geographic landscapes. For the study, two landscape districts of the Leningrad Region (Valdaysko-Tikhvinsky and Luzhsko-Volkhovsky) with landscape mosaics of different structure were selected. The dominant forest types and types of mixed forest stands were determined by summing the areas of each plant association. To carry out the calculations, data of the state forest inventory of the Leningrad Region were used. In the course of this study, it was found that blueberry forest type was the most common forest type in mixed stands. Most of the landscapes of the study region were dominated by spruce-deciduous stands, but in some landscapes with hilly relief, a predominance of spruce-pine stands was observed.


2004 ◽  
Vol 21 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Kerry A. Sokol ◽  
Michael S. Greenwood ◽  
William H. Livingston

Abstract Diameter-limit harvesting has long been suspected as a dysgenic forestry practice, but a conclusive, practical demonstration of the effects of this selection technique on residual tree performance is lacking. To determine the effects of repeated diameter-limit harvesting on the phenotypes of residual trees, we compared radial growth patterns of residual red spruce trees (with ages greater than 100 years) after diameter-limit harvests with those of residual trees in stands subjected to positive selection harvesting. After nearly 50 years of repeated harvesting, residual trees in the diameter-limit stands were nearly 40% smaller and had grown 32% slower than residual trees in positive selection stands. Furthermore, diameter-limit residuals were initially smaller and remained significantly smaller than positive selection residuals throughout their lifespan, despite major release events. After release, the diameter-limit trees responded with increased growth rates, but the increase was relatively small. Growth rates were consistently and significantly lower for diameter-limit residuals until the final 20 yr when growth rates in each treatment converged. Our results indicate that red spruce stands subjected to repeated diameter-limit harvesting will develop progressively less valuable growing stock with limited growth potential.


2003 ◽  
Vol 79 (3) ◽  
pp. 672-684 ◽  
Author(s):  
Louis Archambault ◽  
Jean Bégin ◽  
Claude Delisle ◽  
Mathieu Fortin

Forest dynamics following a partial cut conducted in the early 1950s in the Lac Édouard Experimental Forest in the Mauricie National Park, Quebec, Canada, were studied. Changes in vegetation were analyzed for the period between 1946 and 2001 in 109 mesic stands of the sugar maple – yellow birch bioclimatic domain. Three cutting intensities were considered: 1) low intensity, 15–30% of the basal area; 2) moderate intensity, 30–45% of the basal area; and 3) uncut. More than fifty years following cutting, the original relative proportion of the deciduous and softwood species was maintained. The relative proportion of basal area occupied by softwood species relative to the total basal area varied only from 2.0% to 7.4%. Red spruce (Picea rubens Sarg.) basal area increased in forest types Cornus (Co) and Oxalis-Cornus (O-Co) whereas balsam fir basal area decreased. In the Viburnum-Oxalis (Vi-O) forest type, sugar maple (Acer saccharum Marsh.) basal area increased and yellow birch (Betula alleghaniensis Britt.) decreased. Cutting areas were not invaded by competition species such as mountain maple (Acer spicatum Lamb.). In the Co and O-Co forest types, the regeneration density is probably sufficient to maintain the current cover type. In the Vi-O forest type, where moderate partial cutting was conducted, the deciduous component could substantially increase. Stands reacted positively to partial cutting. The increased growth of residual stems and the arrival of new stems resulted in 2001 total basal areas that were equal to or larger than those observed before cutting (1946). Key words: forest dynamics, partial cutting, yellow birch, red spruce, balsam fir


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